A one-tonne gun smuggled into Iran in pieces by Israeli intelligence agency Mossad was used to kill a leading Iranian nuclear scientist as he drove to his house outside Tehran late last year. Citing intelligence sources, the <em>Jewish Chronicle</em> said on Wednesday that a team of more than 20 agents, including Israeli and Iranian citizens, carried out the ambush on scientist Mohsen Fakhrizadeh after a long surveillance operation. "For eight months, they breathed with the guy, woke up with him, slept with him, travelled with him," a source told the newspaper. "They would have smelt his aftershave every morning, if he had used aftershave.” Iranian media said Fakhrizadeh died in hospital after he was shot as he drove with 12 armed guards to his weekend house outside the capital in November. Giving no further details of its sourcing, the world's oldest Jewish newspaper said Mossad mounted the automated gun on a Nissan pick-up truck and that the bespoke weapon "was so heavy because it included a bomb that destroyed the evidence after the killing". It said the scientist's movements were being tracked by the team of Israeli agents on the ground who triggered the weapon remotely as his Opel car passed the Nissan. The gun was so accurate, the volley of 13 bullets hit only Fakhrizadeh and did not harm his wife, who was sitting 25 centimetres away, it said. The agents then scattered and the source claimed that none of them were captured as Iran rounded up hundreds of people it believed had played a role in the plot. The newspaper said the attack was carried out “by Israel alone, without American involvement”, but that US officials were given some form of notice beforehand. Shortly after the killing, Iran pointed the finger at Israel, with Foreign Minister Javad Zarif writing on Twitter of “serious indications of [an] Israeli role”. Iran had also said that the operation was carried out with a remote-controlled machine gun that blew up after the operation. Israel declined to comment in November and on Wednesday night an Israeli government spokesman responded to the latest report by saying: “We never comment on such matters. There has been no change in our position.” Fakhrizadeh, 59, was long suspected by the West of masterminding a secret nuclear bomb programme. He had been described by western and Israeli intelligence services for years as the mysterious leader of a covert atom bomb programme halted in 2003, which Israel and the US accuse Tehran of trying to revive. Iran has long denied seeking to develop a nuclear weapon. <br/> The <em>Jewish Chronicle </em>report said he became a marked man after another remarkable espionage operation in January 2018 when agents broke into a warehouse on the outskirts of Tehran and spirited away tens of thousands of documents that gave full details of Iran's clandestine nuclear weapons programme. They found many of the documents in Fakhrizadeh's handwriting, which pointed to him being the architect of the concealment. “Analysts realised they were looking at his ink, his fingerprints, his pressure on the paper as he wrote. He was the one who was behind the deception," the source said. "He had led an operation to hide it from the world. From that point, it was just a matter of time." According to the <em>Jewish Chronicle</em>'s report, Iran "secretly assessed that it will take six years" before a replacement for Fakhrizadeh is "fully operational" and that his death had "extended the period of time it would take Iran to achieve a bomb from about three and a half months to two years".